For more than 150 years, dating back at least to Charles Darwin’s writings on sexual selection, scientists have generally considered bird song to be a male trait. The widely accepted view was that bird songs are long complex vocalizations produced by males during the breeding season, whereas such vocalizations in females are generally rare or abnormal.
But over the past 20 years, research has shown that both males and females in many bird species sing, especially in the tropics. For example, our group has studied female song and male-female duets in Venezuelan troupials, a tropical species that sings year-round to defend territories. And we have studied female song in eastern bluebirds, a temperate species in which females sing to communicate with their mates during the breeding season.
Recent findings have shown that female song is widespread, and it is likely that the ancestor of all songbirds had female song. Now, rather than asking why males originally evolved song, the question has become why both sexes originally evolved song, and why females have lost song in some species.
In a recently published study, we reviewed 20 years of research on female bird song and found that the key people driving this recent paradigm shift were women. If fewer women had entered this field, we believe that it likely would have taken much longer to reach this new understanding of how bird song originally evolved. We see this example as a powerful demonstration of why it’s important to increase diversity in all fields of science.
